Ned Flanders, Otto Mann, Kodos, Principal Skinner, Mr. Burns, and Smithers are all the characters we remember since the beginning. Of course Shearer didn't voice Mr. Burns at first, but the voice was close enough. I'd get the guy who did it back then back. The main characters are safe, but the others I mentioned are the background makeup we need. Otto Mann could be voiced by Michael Keaton, he played Beetlejuice l, remember how his voice sounded? There you have it. But I've watched the Simpsons ever since I was small. Harry Shearer is unbeatable. I send out a message to him and I hope he hears me; "Mr. Shearer, you are the background of the Simpsons. You made me laugh and talk about your characters all my life. Don't leave us, the show needs you. Without you, we may not make it up to 30 seasons." that is what the show needs. To beat the others.